TW449969B - Zero-voltage switching circuit with inductance feedback - Google Patents

Abstract

The present invention relates to a zero-voltage switching circuit with inductance feedback for electrically connecting to and driving a hard switching frequency converter of a load. The hard switching frequency converter includes a pair of switches and a source voltage. The present invention comprises: a pair of resonant capacitors electrically connected to the pair of switches in parallel; a pair of auxiliary switches; a pair of diodes electrically connected to the pair of auxiliary switches; a pair of inductors electrically connected to the pair of auxiliary switches, the pair of diodes, and the pair of switches. The present invention is characterized in producing a current to flow through the pair of switches when the voltage drop on the pair of switches is zero during the operation of the pair of switches to thereby decrease the switching loss of the pair of switches.

Description

449 9 6 9 V. Description of the invention (1) This case is a dust-switching circuit of the electric-boiler, which is a type of inductive feedback, especially the soft-industry industry, which usually uses f for power-circuit ° hard type Switching wave width modulation (Hards's power electronics control technology, mostly adopts watt-watt dc / ac inverters for shore = ichlng _. In the range of 10 watts to 500 Ω, the heart's view is used as a voltage type. The inverter has the maximum power of the frame: f One is the voltage-type inverter base piece y using wave width modulation technology. In the wooden structure, the unidirectional switching element that can use the gate to close is usually the most j Require = antil-paraUei diode In the case of conductive impedance and easy installation, switch the package of the package. 卞 j characteristics This it f is easy to control and low in cost, but due to the switching of the switching element ,, S adds the switching loss and also causes a surge effect, the quality of the body 'a and interferes with the surrounding electronic equipment and electricity; Second, because of the heat dissipation problem of the switching element, the wave width modulation will be limited = the switching frequency is limited and cannot be Therefore, it is difficult to obtain good performance in AC motor drive applications. Lower noise. In order to improve the above disadvantages, the switching frequency must be increased, but the switching loss will also increase. Therefore, various soft switching applications have been proposed one after another. In general, ^ switching can reduce switching losses, making The switching frequency of the inverter is ^ high, ^ low audible noise and harmonics. And when the switching element is in soft switching, its voltage and current switching stress (dv / dt, di / dt) is also relatively reduced. The suppression of interference (EMI) and torque ripple is also helpful. However, because the soft switching circuit uses the inductance-capacitance resonance principle, the resonance element and related switching elements need to withstand high voltage or large current. Because:

449969 V. Outline of invention —-= = = and can reduce or eliminate high voltage caused by resonance.% WL will be an important issue. The hard-switching characteristics of the switch that has been used without buffer circuit are as follows. The simulation is to use PSPICE to simulate the hard-switching of the switch. The simulation conditions set are as follows: Body switching frequency

Vs = 650 volts I 〇 = 1 50 amps BSM200GA120D MUR2520 10 K Hertz Figure 1 shows the analog circuit diagram of a hard switch. Figure 3 is a hard-switching characteristic diagram of the switch. The simulated waveforms are the gate voltage Vgp of the upper switch in one arm. The gate voltage Vgn of the lower switch, the collector-emitter voltage Vce of the upper switch, and the collector current I. c. Switching of upper switch and conduction loss dagger. ". Figure 4 shows the hard-switching characteristics of the switch-enlarged view during the on-time period, Figure 5 1 is the hard-switching characteristics of the switch-enlarged view of the cut-off period. The average loss is 5.03KW 〇 2. The switch with a buffer circuit is used The hard switching characteristics are as follows. The simulation conditions are: DC bus voltage + 6 50 volt load current peak 150 amperes.

IGBT BSM200GA120D flywheel diode MUR2 520 switching frequency 1 0 KHz

D: \ champion \ CASE \ po_new \ pdl567. Ptd Page 5 449969 Five 'invention description (3)-Buffer capacitor 0.25u Farad Buffer capacitor design value can be obtained from the voltage switching rate we specified, # The following formula can be obtained Get the capacitance value. Meaning C (dv / dt) = Isw 〇 Isw / (dv / dt) (2. 11) where C is the buffer capacitor value, I sw is the switch switching current, and dv / dt is the voltage switching rate. We specify dv / dt as 75 0 and Isw as 150 amps. The capacitance can be found to be 0.2 u Farad. Figure 6 is an analog & diagram of a hard switch with a snubber circuit.圊 七 is a hard-switching 4-phase simulating diagram of a switch with a snubber circuit. The simulated waveforms are the gate voltage Vgp of the upper switch in one arm, the gate voltage Vgn of the lower switch, and the collector of the upper switch- Emitter voltage vce, collector current I c, switching of the upper switch and conduction loss PUs4, .. Figure 8 Hard-switching characteristics of the switch-Enlarged image during conduction, (Figure & 4 Hard-switching characteristics of the switch- The figure is enlarged during the cut-off period. The average loss of hard switching of the switch with buffer capacitor is 11 _ 6 5KW. The Ic and PLoss in Figures 4, 5, 8, and 9 are assembled into Figure 10. From the figure, we can see that the parallel connection The snubber capacitor can be changed to a higher level on the switch _ ^, and learn to reduce the number of cut-change-time-slips. However, during the turn-on period, the turn-on current and turn-on switching loss of the turn-on switch will increase. And, it is necessary to increase the current rating of the switch, so using a parallel buffer capacitor on the switch to improve the voltage switching rate of the switch must carefully consider the capacitor value to find the equilibrium point.

D: \ diampion \ CASE \ po_new \ pdl567. Ptd page 6 449969 V. Description of the invention (4) This case is a kind of electric drive that simultaneously drives a load ~: Award: Zero voltage switching circuit '$ Hard switching with electric connection Frequency converters are often used to avoid shortcomings such as general losses. In the case of the dog wave effect, electromagnetic interference and frequency switching, the inductance of the case is returned to the moving-load-switching circuit. It is electrically connected and pushed to the switch and a source voltage, and the state is ^ =. The hard-switching inverter includes a Pair of switches; a pair of auxiliary 13 pairs of resonant capacitors, which are electrically connected in parallel to the auxiliary switch; and ~ pair of j, which is a pair of diodes, which is electrically connected to the pair of diodes and the pair of power switches 4, which are electrically connected To the pair of auxiliary switches, and between them, the "characteristics of the pair of switches is to make the pair of switches to switch during operation to reduce the: 2 when it drops to zero 'generated-the current flows through the above, Dragon 2 switch The switching loss is used to provide the source voltage included in the entire Φ hard hard-switching inverter. &Quot; The selection of the circuit operation is as described above. The t Φ package includes-the first transfer switch remote hard-switching inverter contains The on-off relationship switching switch is electrically connected 'and the second switching on 11' is connected to the first and tortoise in parallel with the load. Electricity, I: ϋ · 1 = two, where the first switching on relationship includes a first — Terminal, the high voltage of the source voltage And-the second terminal, and the second switch includes a first terminal, which is electrically connected to the second terminal of the first switch; and a second terminal, which is electrically connected to the source voltage As mentioned above, wherein the pair of inductors includes a first inductor; and the first inductor includes the inductor including a first terminal; and the first inductor is connected in parallel with the first inductor to a first End and a second end. Also, the first

D: \ champion \ CASE \ po—new \ pdl567 ‘ptd page 7 449969 V. Description of the invention (5) and a second terminal, which is electrically connected to the second terminal of the first inductor. As described above, the second terminal of the second inductor is electrically connected to the second terminal of the first switch. And the second terminal of the second inductor is electrically connected to the first terminal of the second switch. As described above, wherein the two auxiliary on relationships include a first auxiliary switch and a second auxiliary switch. The first auxiliary open relationship includes a first terminal connected to a high potential of the source voltage, and a second terminal. And the second auxiliary switch relationship includes a first terminal which is electrically connected to the second terminal of the first auxiliary switch; and a second terminal which is electrically connected to a low potential of the source voltage. As described above, the first terminal of the second auxiliary switch is electrically connected to the first terminal of the second inductor of the reverse-polarity transformer. As described above, the pair of diode systems includes a first diode and a second diode. The first two-pole system includes a first terminal which is electrically connected to the first terminal of the first auxiliary switch; and a second terminal which is connected to the first inductor of the reverse polarity transformer. The first terminal is electrically connected. And the first end of the first diode is electrically connected to the first end of the first switch. In addition, the second diode system includes a first terminal electrically connected to the second terminal of the first diode, and a second terminal connected to the second terminal of the second auxiliary switch. The terminal phase is electrically connected. And the second end of the second diode is electrically connected to the second end of the second switch. As mentioned above, the zero-voltage switching circuit of the inductance feedback can be a three-phase zero-voltage switching circuit of the inductance feedback, for electrically connecting and pushing

D: \ champion \ CASE \ po_new \ pdl567 · ptd Page 8 449 9 6 9 V. Description of the invention (6) One of the loads is a hard-switching inverter. The hard-switching inverter includes three pairs of switches and three source voltages. As mentioned above, the three-phase inductive feedback zero-voltage switching circuit includes three pairs of resonant capacitors, which are electrically connected in parallel with the three pairs of switches; three pairs of auxiliary switches; three pairs of diodes, which are electrically connected to the three Pair of auxiliary switches; and three pairs of inductors, which are electrically connected to the three pairs of auxiliary switches, the three pairs of diodes, and the three pairs of switches. In this case, you can gain a deeper understanding through the following diagrams and descriptions: Figure 1: Basic structure of a voltage-type inverter using wave width modulation technology Figure 2: Simulation of a hard-type switch Figure 3: Hard-type switching of a switch Characteristic diagram. Figure 4: Hard-switching characteristics of the switch-Enlarged view during conduction. Figure 5: Hard-switching characteristics of the switch-enlarged view during cut-off. Figure 6: Simulation diagram of a hard-switch with a snubber capacitor. Figure 7: A hard-switching characteristic diagram of a switch with a snubber capacitor. Figure 8: Hard-switching characteristic diagram of a switch with a snubber capacitor-enlarged view of the conduction switch. Figure 9: Hard-switching characteristic diagram of the switch with buffer capacitor-enlarged view of cut-off switching. Figure 10: Comparison of hard-switching collector current and switching loss of a switching switch without and without a buffer capacitor: (a) and (b) Comparison of collector current and switching loss during on-time switching;

D: \ chaiiipion \ CASE \ po_new \ pdl 567. ptd Page 9 449 9 6 9 V. Description of the invention. (7) Figure X. The following day is right ,;-Figure X-'Zero voltage containing electric dumplings Switch circuit diagram. Brother 4 feedback of the single-sleeve switching circuit (C) and (d) of the electric survey switching are the goods diagrams at the time of cut-off switching +-: ~ 4 period set extremely low life + so 'phase contains 赍 rf a chance Comparison of switching losses. Illustration. Figure 12 contains the operation of each mode. Single-arm switching circuit for zero voltage switching by Q. Figure 14: Single-arm switching circuit for zero-voltage switching containing the relevant waveforms of various modes of electric Rui σ Λ. Figure 15: Human =. Road illustration. 3 Inductive feedback of the zero-voltage switching circuit simulation electric diagram 16. Containing electricity salt ^ Simulation complete diagram of each mode: zero-f switching of the single-arm switching circuit (a) of the main switching vibration pq, change the switch卩 of the arm S4, the closed 'emitter voltage Vge (Sl)' of S1

Gate-emitter f voltage Vge (S4) of Sxl, upper arm of auxiliary switch ^ ^ Vge (Sxl); (b) Inductance | 、、 ά τ current ι_; μ LS1 'Iris synthetic current Usl + iLS2, load m Di, m conduction current 1d (up boil current π, lower arm current i4) ^ charge and discharge 1 of resonance capacitors C1 and C4; current iniiC4; collector of switch S1 ~ emitter voltage vce (s 1), Collector current

Ic (Sl); (g) collector-emitter voltage Vce (Sxi) collector current of auxiliary switching switch Sxl I c (S X1);

D: \ champion \ CASE \ pojiew \ pcU5ti7. Ptd page 10 4499 S 9 Jade and invention description (8) (h) Main switch power loss dagger (§1); (Π auxiliary switch power loss pL Coffee ( Sxl); (j) Inductive power loss P_ (LS1); (U Inductive power loss Plqss (Ls2) !! Table 1: Power loss comparison between hard and soft switching

Vs Vgn Vc e Ic

Current drain voltage Vgp: Gate voltage I of upper switch and lower switch I Collector-emitter voltage collector current of upper switch rLOSS SI ~ D1 ~ Lsi, switching of upper switch and conduction loss S6: changeover switch Sxl ~ Sx6: auxiliary Training, Dxl ~ Dx4, Dp, Dn: diode meter '

Ls2: Inductance C1 ~ C6: Resonant capacitor Please refer to Figure 11 ’Three-phase zero with inductance feedback =

The main structure is to add a resonance circuit on each arm of the hard-switching inverter: the second resonance branch is connected to two auxiliary switches, a reverse polarity changing mother gain with a turn ratio of i, two diodes and two resonance capacitors D The added resonance branch will only operate when the main switch of the inverter is switched to turn 4. The resonance behavior formed by the auxiliary switch's conduction can make the switch to be conductive under zero voltage conditions and near zero voltage conditions. Under wear only. If the control signal is optimized, the auxiliary switch can be turned on and off at zero current. The operating time of the resonance circuit occupies only a very small part of the entire switching cycle, so that the rating of the auxiliary switch is much higher than that of the main switch

I ·

Page D; \ champion \ CASE \ po_new \ pdl 567, ptd 449969 5. Description of the invention (9)-much smaller. Although the resonant capacitor can use the stray capacitance of the switch, it is actually added with the capacitor, so that the capacitance value is appropriate and more aggressive, the voltage switching rate d v / d t at the time of the switch can be reduced. In 'Switch p ^ Decision of switching control signal', the switching characteristics of the main switch zero electric dust β and auxiliary off zero current can be analyzed. 'The switching control of the hard-switching inverter is appropriately delayed and the auxiliary switch control signal is added. Printing can be completed softly ^: change, without the need to use the zero voltage detector of the switch voltage or current. People 1 cut 'The following is a three-phase zero-voltage switching circuit containing an inductance feedback: a model to be analyzed. Because each arm of this three-phase circuit can be operated separately, we will analyze the circuit shown in Fig. 12 into seven modes: its single-arm switching potential-m.-The return of the thirteenth, single-arm switching The related waveforms of each mode of the circuit are shown in Figure 14. (a) Mode 1 (t 0 ~ 11): As shown in Figure 13 U), the initial condition is that the main switch S1 is on and the main switch S 4 is turned on. The load current flows through the anti-parallel diode M ^ (b) Mode 2 (t b t2): As shown in Figure 12 (b). At 11:00, s 4 is still on. $ Χ 1 is turned on, so the DC hidden voltage Vs across the inductor Ls2, so the auxiliary inductor current rises linearly. Since LSI = LS2, so = 丨 ⑽, the inductor current and the current flowing through diode D4 share the load current. At 12 o'clock, the inductor current rises to one-half the load current, and the load current flowing through diode D4 is completely transferred to the inductor current, so diode D4 is naturally cut off at this time. (c) Mode 3 (12 ~ 13): '°

Page 12 449 9S 9 V. Invention-Figure 13 (c) is shown in Christine. After t2, the DC bus voltage is still across the inductor 1 ^, so the inductor current continues to rise. At t3, the amount of current rising enough to cause the main switch to switch under zero voltage conditions. (d) Mode 4 (t3 ~ t4): Ugly as shown in Figure 13 (d). At t3, s4 is turned off. At this time, the LC and vibration periods are entered, and the capacitor voltage across S1 drops to zero voltage at t4. (e) Mode 5 (t4 ~ 15): As shown in Figure 13 (e). At the time, the diode starts to conduct and passes through the current. At this time, the voltage across the inductor LS1 is a negative DC bus voltage (~ Vs), and the inductor current starts to decrease linearly. At t5, when the inductor current drops to half the load current, the diode βι is cut off. Between t4 and t5, the main switch S1 can be turned on under the condition of zero voltage. (f) Mode 6 (t 5 ~ ΐ 6): As shown in Figure 12 (f). After 15, the inductor current continues to decrease linearly and the main switch S1 begins to conduct current. At t6, the inductor current drops to zero and the load current is completely conducted by phantom conduction. (G) Mode 7 (t6 ~ t7): As shown in Figure 12 (g). After t 6, the inductor current is zero, and the auxiliary switch Sx 1 is turned off at zero current when delicious. In order to verify the zero-voltage switching circuit with inductance feedback in this case, I simulated as follows: ’Early simulation conditions are: DC bus voltage 6 5 0 volts Peak load current 1 50 amps

D: \ champion \ CASE \ po „new \ pdl 567. ptd p. 13 449969

BSM200GA120D MUR2520 V. Description of the invention (11)

IGBT flywheel diode switching frequency snubber capacitor snubber inductance 1 0K Hertz 0 .1 5 u Farad 3 u Henry Road, the analog circuit containing the zero voltage switching circuit of the inductance feedback is defined as positive in the figure ^^ direction . S1's imitated bimorph + six, shown. ® In the main switch, the -il emitter voltage Vge (S1) on the main switch, the gate-emitter of the lower arm S4 of the main switch ^ goes to Vge (S4), the gate of the auxiliary switch δχ1 gate_emitter voltage ΪΪχ1) ^ ^ Electric training L_, the conduction of one pole sister D1, D4. Current ID1, ID4 'upper arm II, lower arm current 14' resonance capacitor, and charge / discharge current Ici and machine Ic4 of 0, main switch S1's collector voltage Vge (si), collector current Ic (Sl), collector-emitter voltage Vce (sxi) of the auxiliary changeover switch Sxl, current only Ic (Sxl), main switch power loss pioss (si), auxiliary The switching power loss Pi0ss (Sxl), the inductor power loss pioss (Lsi), P1oss (Ls2). Figure 16 (f) shows that the main switch is turned on at zero voltage and is turned off under approximately zero voltage conditions, eliminating current surges and voltage switching stress during the on period. The average power losses of the main switch si, the auxiliary switch Sxl, the inductor Lsl, and U2 are calculated from (h), (i), (j), and (k) in Figure 16 as Ploss (Sl) = 448W 'Pioss ( Sxl) = 132〇w,

Pl〇SS (LSl) = 0_23W, P1〇ss (Ls2) = 11.84w, the total power loss is

D: \ champion \ CASE \ po_new \ pdl567.ptd Page 14 4 49 9 09 87120766

V. Description of the invention (12) 1820 [Comparison of power loss between hard and soft switching is shown in Table 1. 'Comparison of power loss between hard and soft switching i Γ ~~ τι ~~ ^

Thunder θ ϋ: Because of the auxiliary opening, the stray capacitance between the collector and the emitter of Sxi = the on-voltage and spans the auxiliary open circle set:

Sxl cut-off V: The voltage value is the DC bus voltage Vs. When the stray capacitor voltage value of the two or two switches of the auxiliary switch, such as Gamma, will not help the collector and emitter voltage of the switch M to be maintained between π of the on voltage and the auxiliary switch s, it is much larger than the auxiliary switch s. X1 on-time. Comparing the proposed soft-switching inverter with the hard-switching inverter, the proposed inverter can reduce current, electromagnetic interference and improve efficiency. Compared with the two-piece hard-switching inverter, the power and power consumption of the resistor can be avoided, which can greatly improve the efficiency. Kominato-Secondary: In the soft frequency conversion state, “Although the instantaneous value of the current of the auxiliary switch I main switching female hW”, but its operating time is very short, so you can use a switching element with a lower rating than the main knife switch. As shown in the simulation diagram, the f-rate loss of the soft switching is much smaller than the power loss of the hard switching. Therefore, it is allowed to operate the switch under the condition of local current to increase the utilization rate of the switching element. To increase the utilization rate of the switching element is to reduce the size of the inverter and the: key. Reducing the size of the inverter can increase the energy density, and the switching element may be more widely used at K due to the reduced cost. In order to _improve the hard switching to become disadvantages, we can switch from soft switching

Page 15 4499S 9 Case number 87120766

V. Description of the invention (13) The inverter obtains the following advantages: Reduces the reliability of the electric inverter of the switch and reduces the voltage and current of the switch. By increasing the wave width modulation and the DC bus capacitor can reduce the output of the inverter. The voltage surge reduces the flow. Because the voltage and current are not disturbed. You can choose smaller apparent power capacity, input / output filters and slow weight. It may also reduce costs. It is particularly important to mention that the circuit can be operated individually, so there is no overvoltage type soft switching when other soft switching modes are used. The inverter enables the single-arm mode to be used in uninterruptible power systems and two-way straight. It can be used in harmonic elimination of motor drivers. Therefore, the shortcomings of the switching technology and the switching stress of the voltage or current are small, and the snubber c is rated. The switching frequency can improve the output current characteristics and reduce the switching rate of the voltage, which can reduce the level of the coil insulation material and reduce this. To improve i rcu it), it is necessary to control the leakage leakage rate of the bearing due to the small number of long wires. Therefore, it can reduce the switching rate of the rated electromagnetic dry rate, the direct current circuit, and the bus current. Therefore, the size of the inverter can be reduced. The current motors used by single or large electric appliances for single appliances and in the public can be converted to any motor flow. Because of the arm and single category. The driver uses electric power to switch to the device. The three-wave wide modulation conversion mode is converted to single-phase, three-phase, and single-phase mode. Technology also switched to regenerative boom operation, these three modes. This mode can be used in the three-phase mode to compensate for the virtual work and consumption. It can improve the hard use.

PC11567-fix.ptc 16th stomach

Pdl567j # E.ptc Page 17 4 49 9 6 9 years

Case number 87120766

Pdl567-fix.ptc page 18

Claims (1)

4499 6 9 _87120766_ Month: 30LS-3ua; Supplementary Amendment VI. Patent Application Scope 1. One kind of electric load is off and one source is one on one pair. One pair of switches is low. The pair is on. 2 Such as the application circuit, where the entire circuit 3. If the application circuit, one of the first cut a second connection is connected in parallel 4. Such as the application circuit, where the feedback hard-cut voltage is sensed, the resonant electric assisted open diode inductor '; The patent of its extreme pressure drop off is the patent of the hard operation. The patent of the hard operation is the switching of the switch for the switching load. The patent range is the first-to-first terminal, which is the second terminal. 5. The zero-voltage switching circuit as claimed in the present invention is used to electrically connect and push a replacement inverter, and the hard-switching inverter includes a pair of switches which include: "Electrical connection in parallel with the pair of switches; Off;" Electrical connection to the Pair of auxiliary switches; and are electrically connected to the pair of auxiliary switches, the pair of diodes, and the characteristic is that during the operation of the pair of switches, the pair of switches is zero 'generated-a current flows through the pair of switches to reduce the loss ^ The source voltage included in the zero voltage switching electric switching inverter of the inductance feedback described in item 1 is used to provide power. The zero voltage switching electric switching inverter included in the inductance feedback described in item 1 includes the folio relationship including:; and is electrically connected to the second switching switch, and electrically connects the inductance feedback described in item 3 The zero-voltage switching electrical switching on relationship includes: the high potential connected to the source voltage; and the zero-voltage switching electrical circuit of the inductance feedback described in item 3 of the patent scope. Page 19 449969 Amendment 6. The scope of the patent application, wherein the second switch-on relationship includes & -end, which is electrically connected to the far first end of the -change switch, and a second end, which is electrically connected to the source The low potential of the electric voltage, 6. The zero-voltage switching circuit of the inductance feedback according to item 1 of the patent application scope, wherein the pair of inductors includes: a first inductor; and a first inductor connected to the first Inductor Yilian is an inductance feedback / voltage switching circuit as described in the sixth item of the patent application scope, wherein the -inductor includes the first terminal V and a second terminal. 8. The inductance-return zero-voltage switching circuit according to item 6 of the patent application claim, wherein the second inductance includes: a first end and an electrical connection with the first end of the second inductor 9 The zero-voltage switching circuit of the inductance feedback as described in item f of the patent application range, wherein the second end of the second inductance is electrically connected to the zero of the inductance feedback by the first phase of the first switch. The voltage switching circuit, wherein the second terminal of the second inductor is electrically connected to the first terminal of the second switching switch. 11. As described in the patent application, the zero-voltage switching circuit of the inductance feedback is described in which :::. Xiang Yi No. ^ auxiliary switch and-No. τ ° 褒 '' auxiliary opening relationship package food auxiliary switch. 1 2 The zero voltage switching of the inductance feedback of S1 in Shenshe $ 1A in the May 11th patent scope I called 丨 R% History? Ann 0 1 0. As described in item 8 of the scope of patent application-end system and 1 volt 4 49969 Amendment Case No. 87120766. Year G, Amendment VI, Patent Application Fanyuan Circuit, where the first auxiliary open relationship includes:-the first terminal, which is a high potential electrically connected to the source voltage; and a second terminal . 1 3. The zero-voltage switching circuit of inductance feedback according to item 11 of the scope of patent application, wherein the second auxiliary open relationship includes:-a first terminal, which is connected to the second terminal of the first auxiliary switch Phase electrical connection; and a second terminal, which is electrically connected to a low potential of the source voltage. 1 4. The zero-electricity M switching circuit of the inductance feedback according to item 11 of the scope of patent application, wherein the first terminal of the second auxiliary switch is in phase with the first terminal of the second inductor of the reverse polarity transformer. Electrical connection. 1 5. The zero-voltage switching electrode circuit of inductance feedback as described in item 1 of the scope of patent application, wherein the pair of two-pole system includes a first diode and a first 6. According to item 15 of the scope of patent application The zero-voltage switching circuit for inductive feedback, wherein the first two-pole system includes: a first terminal, which is electrically connected to the first terminal of the first auxiliary switch; and a second terminal, which Is electrically connected to the first end of the first inductor of the reverse polarity transformer. 17. The inductive feedback zero-voltage switching circuit according to item 16 of the scope of the patent application, wherein the first terminal of the first diode is electrically connected to the first terminal of the first switching switch. . 1 8. Zero-voltage switching of inductance feedback as described in item 15 of the scope of patent application Pdl567-correction. Ptc page 21 4499 6 9 seat number 87V20766 ° \ year e-iL- > full winding positive connection 6. Patent application circuit 'where the second two-pole system includes: a first-' end, which It is electrically connected to the second end of the first / second body and-the second second end, which is electrically connected to the second end of the second #M switch, such as the 18th in the scope of patent application In the zero-voltage switching circuit of the electrical feedback, the second terminal of the second diode is electrically connected to the second terminal of the second switch. 2 〇 The zero-voltage switching circuit for inductance feedback described in item 1 of the scope of the patent application, wherein the zero-voltage switching circuit for inductance feedback may be a three-phase zero-voltage switching circuit for inductance feedback. A hard-switching inverter that electrically connects and drives a load. The hard-switching inverter includes three pairs of switches and three source voltages. 21. The zero-voltage switching circuit for inductive feedback as described in item 20 of the scope of patent application, wherein the three-phase zero-voltage switching circuit for inductive feedback includes: three pairs of resonant capacitors, which are electrically connected in parallel with the three pairs Switches; two pairs of auxiliary switches; three pairs of diodes, electrically connected to the three pairs of auxiliary switches; and three pairs of inductors, electrically connected to the three pairs of auxiliary switches, the three pairs of diodes, and the three pairs of switches. 22. The zero voltage switching circuit of the inductance feedback as described in the first item of the patent application scope, wherein the pair of inductors are connected as a reverse polarity transformer. ' Pdl567-fix.ptc page 22